My stock 1/2" temp probe obviously won't work with the threaded 3/8" ports in my new heads...
Anyone have a P/N for a 3/8" temp probe that works with the stock gauges in a 79?


Also: Where should coolant temp probes go? -Is it better to use the threads in the heads, or should I be using a threaded port in my intake just before my thermostat?
(I want to use a sensor that works with the stock gauges but I've got a 2nd temp probe for my Holley EFI; right now I have it installed in the intake, but now I'm wondering if the temps in the head are more important / relevant...???)


Adam

 

Are your heads already installed? If not, take the passenger side head to a machine shop. They can drill and tap for the correct size hole for the probe. They charged me $30.

Just strictly my opinion, but I think there is enough crap in the way at the front of the intake, near the thermo. That's why I wanted to use the NPT port in my aluminum head. Just kind of cleans things up, out of sight, out of mind.

 

I prefer them in the heads on my cars

 

Autometer sells a 1/8 with adapters for 3/8 and 1/2. Worth a call to them if you already have the heads installed and in the car.

 

What heads, just curious.

 

The heads are on right now for degreeing the cam, then I have to take the heads off again. I don't REALLY want to have to drill and tap the heads this late in the game, if I can just buy a "compatible" temp probe that will work with the stock gauge.
[Edit] The passenger-side head is fully installed and torqued down; the driver's side is NOT permanently installed yet.

Adam

 

Profiler 195cc "Jegs" rebranded.
I like the idea of having a "#'s matching L82 350, stock bottom-end with "just some aluminum Jegs heads, and a TPI intake" but making a surprising amount of power for what it is. I REALLY want to get "SMOG MTR" for a vanity plate.
Bottom-end is a stock L82 rebuilt but it was ultra low mileage so no overbore: stock forged crank, stock pistons, stock rods, with 1.2mm gapless rings.
Profiler 195cc heads, but they just say "jegs" on the end (valves and guideplates are all that I kept that came with the heads) New PAC 1219x Beehive Springs, new 10 degree retainers and locks, new viton valve guide seals, 7/16" studs, polished exhaust ports, polished the exhaust side of the chamber.
1.6 Comp Ultra Pro Magnum rockers, Mike Jones custom roller cam, FIRST fuel injection TPI-style intake (flows almost 300cfm on the crappiest runner), Holley HP EFI, Bosch 4 36lb injectors, 58x crank trigger wheel, & LS Truck coils.
I want to mount the coils stealthily, but I'm not sure how. The cam sync sensor gives away that this isn't a "normal" SBC with a distributor; I've seen the custom LS coil mounts that go in an arrangement that looks KINDA like a distributor but I don't think it will fit with the cam sync sensor there... Might just tuck them under the block out of sight... Obviously, haven't figured out coil mounting yet; need the heads and intake installed and the engine back in the car, first...


Adam

 

The passenger-side head is already installed fully and I used copper coat on the shim gasket so I REALLY don't want to take it off.
The driver's side isn't fully installed yet, so if I'm going to get it opened up it would have to be on that side... -I'm pretty sure my Holley temp sensor is 1/2", too, though.


Adam

 

Adam, it's really not a big deal to drill and tap the head for the larger stock sensor. I know people have had trouble with aftermarket smaller sensors not reading properly. Just tape up your port and chambers and bolt a valve cover on and you shouldn't have any trouble with the aluminum chips getting in anything. It's easy to blow out the water jackets after you drill and tap the head.

Mike

 

Even if all the metal bits aren't removed it won't have much affect and probably not any on the cooling system function. Metal bits in the oil system through drilling holes is an entirely different kettle of fish.

 

I believe Willcox Corvette sells a new 3/8” temperature sending unit now for 79 model.

 

https://willcoxcorvette.com/corvette...79-3-8-npt-new

 

I JUST saw this right when I need it most. Thanks!


Adam

 

want to see this thing run & hear your driving impressions with all that low-midrange tq

 

Get the adjustable temp resistor while you're at it. If you think your temp sender is good, then just take your the temp sender and install it in the intake manifold near the thermostat housing....then dial it in with the adjustable resistor.
I lived with my inaccurate gauge for years and it didn't take much time to install the adjustable resistor... now my gauge is dialed in and works like a dream. I should have done it as soon as the adjustable resistors came out.

https://willcoxcorvette.com/corvette...resistor-77-82

 

*Sigh* Me too. Everything takes me forever, though.

I just had issues with the intake to head bolt holes not lining up right yesterday (stock non-decked block, new heads, intake gasket recommended by MFGR); I SHOULD HAVE just stopped, wiped off all the RTV and taken the time to elongate the bolt holes on the intake, but I REALLY wanted to get it done and thought I managed to just barely be able to start both bolt #1 and #2 in the torque order -they of course went in really tight because they're right against the edge of the intake bolt hole and I didn't realize that at least one went in at a funky angle and I'm quite certain I screwed up the threads in one hole on one head, at least. I just hope I don't have a vacuum leak so I don't have to worry about taking the intake off for like 10 years...

Next I'm going to have to figure out a custom coil mount solution and measure for custom spark plug wires because I have to combine my newbie-ness with doing something unique...

I'm trying to redo the front suspension and paint the engine bay before I put the engine back in so don't hold your breath on me reporting back driving impressions any time soon...


Adam

 

I have a 72 that I am restoring and the engine is on a engine stand. I drilled and tapped mine this weekend. I vacuumed out the chips and used a bore scope there was nothing in the head. I used a 23/32 S&D drill and a 1/2 NPT tap that is a 15degree helix that removes the chips out the back.

 

I've never heard of such a thing. You can use this resistor to adjust what the interior gauge reads? (So technically if you bought a smaller after market temp sensor that the interior gage didn't like AND you had a digital temp sensor with your EFI system (like I have) you could "calibrate" the two together so they read the same?!?

-Then the adjustable resistor thing goes inline between the interior gage and the analog temp sensor?


That's a cool option.
I think I'm going to go with the stupid Wilcox $80 machined stock temp sensor because it's just brainlessly easy and I need SOMETHING easy right about now given what's ahead of me...


Adam

 

The adjustable resistor is attached behind the gauge. I dialed it in to match my EFI digital indication. It is really quite wonderful. Let me see if I can find the installation instructions.

 

here you go. the 77-82 adjustable resistor installation video....

http://repairs.willcoxcorvette.com/w...able-resistor/


I actually have a 3/8" sender in the driver side head to experiment with (someday) and see if it would track with my EFI temp indication. I bought it before I got the adjustable resistor. Once I got the adjustable resistor and it worked so FANTASTICALLY with the original sender next to the thermostat housing....well, I put my experiment off. Someday I'll test it just for funsies.
The generic 3/8" sender was cheap at autozone and it read low (like my 1/2" sender read low) so I suspect that it will be within range of the adjustability of the variable resistor if I ever get around to playing with it.